Liquid-measuring apparatus.



G. H. GIBSON.

LIQUID MEASURING APPARATUS.

APPLICATION FILED IIJBJ, 1911.

Patented D60. 31, 1912.

a SHEETS-SHEET 1.

IN VE N TOR A TTORNE' Y WITNESSES -G. H. GIBSON.

LIQUID MEASURING APPARATUS.

APPLICATION FILED rmm, 1911 1,048,677, Patented Dec. 31, 1912.

3 SHBETSSEBET 2.

IN VE N TOR WITNESSES A TTORNE Y G. H. GIBSON.

LIQUID MEASURING APPARATUS.

APPLICATION FILED 11111.1,1911.

1,048,677. Patented Dec.31, 1912.

3 SHEETS-SHEET 3.

IN VE N TOR WITNESSES :i) i gigg flQ/gwdm,

A TTORNE Y 0/ UNITED STATES PATENT OFFICE.

GEORGE H. GIBSOZN, 0F MON'ICLAIR, NEW JERSEY, ASSIGNOR TO JOSEPH S.LOVERING WHARTON, WILLIAM S. HALLOWELL, AND J OHN C. JONES, ALL OFPHILADELPHIA,

PENNSYLVANIA, A FIRM.

LIQUID-MEASURING APPARATUS.

companying drawings, which form a partthereof.

My present invention relates to apparatus for measuring the rate of flowof a liquid over a weir, and particularly to apparatus in which the rateat. which a liquid like water, of varying temperature flows through oneor more V-shaped notches formed in the upper edge of a weir, isdetermined by measuring the variation in the amount of liquidaccumulating on the supply side of the weir above the weir notch bottomlevel.

The object of my invention is to provide corrective or compensatingprovisions whereby the weight of the liquid flowing can be determinedwith the desired accuracy notwithstanding the changes in the density ofthe liquid which occur with changes in its temperature.

While the invention is of general utility, it is particularly useful,and the apparatus disclosed was primarily devised for use in measuringhot water varying in temperature over a substantial range by means ofthe apparatus forming the subject matter of my Patent No. 1,015,556,granted Jan. 23, 1912, and my copending application, Serial No. 605,878,filed February 1st, 11, wherein I have disclosed and claimed novelprovisions adapted for measuring with a weir the hot water dischargedfrom heaters of the kind commonly referred to as open feed waterheaters. In my said patent and copending application I disclose meansfor measuring the variations in height above the bottom of the weirnotch or notches, of the water level on the supply side of the weir,directly by means of a float, and indirectly by measuring thehydrostatic pressure at a determined level below the surface of thewater on the supply side of the weir. With such ap- Specification ofLetters Patent.

Application filed February 1, 1911.

Patented Dec. 31, 1912.

Serial No. 605,880.

paratus the temperature of the water in practice not uncommonly variesfrom about 120 Fah. to 220 Fah. The variations in temperature of thewater result in changes in its density, and the changes in density will,if not corrected or compensated for prevent the apparatus from trulymeasuring the weight of water flowing except when the water is at thetemperature for which the apparatus is calibrated.

The character of the provisions necessary to correct or compensate forthe changes in density of the liquid flowing depend to some extent uponthe character of the measuring apparatus. The general laws governing theflow of liquids over weirs, and particularly the flow of water throughV-shaped notches formed in weirs, have long been known. The mostcommonly used formula for the rate of flow of water through a rightangled weir notch is:

where V is the number of cubic feet per minute flowing through the notchand H is the height in inches of the water level on the supply side ofthe weir above the bottom of the notch. \Vhile the formula just given issutliciently accurate for most purposes, the value of the constant .305given above, varies slightly with variations in H, and the rate of Howvaries also generally, but not exactly with the value of the tangent ofhalf the angle of the weir notch. I have found with weirs and notchessuitable for use in measuring the water discharged by an open feed waterheater, where H ordinarily does not exceed ten or twelve inches and 0,the angle of the weir notch, is ordinarily about 90, that a highlyaccurate and general formula for the rate of flow is:

V 0.316 tangH Since W, the number of pounds of water flowing per minuteequals 1728 VD, where D is the weight of a cubic inch of water, andsince I, the hydrostatic pressure on the supply side of the weir at thelowermost level of flow over the weir in pounds per square inch, isgiven by the equation P HD, the equation for the rate of flow givenabove may therefore be converted into either of the following equations:

W= 546.048 tangDH tang hDHTIfiPZA'IS The first of the last two formulaeis one which I employ in determining the rate in pounds per minute ofliquid flowing where I measure the accumulation of liquid on the supplyside of the weir by measuring the height of the liquid level above thelowermost level of flow over the weir by means of a float or the like.The second of these equations is one which I employ when I measure theaccumulation of liquid on the supply side of the weir by determining thehydrostatic pressure on that side of the weir at the lowermost level ofoverflow. W'lth the first of these equations, it is apparent that inorder to have the weight of liquid flowing constantly for any givenvalue of H, the quantity must remain constant; and with the otherequation the quantity D tan.

must remain constant if the weight of liquid flowing for any given valueof P is to remain constant. This means in the first'case, that as thetemperature of the liquid increases and D, the-density-correspondinglydecreases, the relation between N and H expressed by the formulamay bepreserved by increasing the angle 6) of the weir notch. Similarly in thesecond case, to preserve the relation between W and P, the angle'@) ofthe weir notch must decrease as the temperature of the water increases.I find that with either formula, I obtain results accurate enough forpractical purposes and indeed approaching very closely to theoreticalaccuracy in the case of the ordinary temperature range of water issuingfrom an open feed water heater employing thermostatic mechanism toincrease and decrease the weir notch angle as the temperature of theliquid increases or decreases where the flow is deter mined by measuringthe height of liquid level, and to decrease and increase the weir notchangle as the temperature of the liquid increases and decreases where therate of flow is determined by the hydrostatic method.

In addition to the above described methods of adjusting the apparatus tocompensate for the variations in the relation between the rate of flowand the measurement thereof, which the change in density tends tointroduce, it will be apparent that other methods of adjustment may beemployed. For instance, if the weir be raised and lowered with respectto the measuring apparatus when theoretically the rate of flow should bedecreased or increased to compensate for the change in density of theliquid flowing, increased accuracy may be obtained, and in practice, avery substantial approxi mation toward absolute accuracy may beobtained, when the rate of flow does not vary greatly from the averagerate of flow, by raising and lowering the weir with relation to themeasuring apparatus in direct or inverse proportion to the changes intemperature of the liquid flowing, depending on the character of themeasuring apparatus.

I have hereinafter described in detail, certain arrangements in whichthe apparatus is adjusted in the various ways referred to above, andhave illustrated these arrange ments in the accompanying drawings ofwhich:

Figure 1 is an elevation partly in section, of water heating andmeasuring apparatus embodying the present invention. Fig. 2 is anelevation taken atright angles to Fig. 1, of a portion of the apparatusshown in the latter figure. Fig. 3 is a plan of the apparatus shown inFig. 2. Fig. 4 is a partial elevation taken similarly to Fig. 2 but on alarger scale. Fig. 5 is a view taken similarly to Fig. 4, but showingthe parts in dif ferent positions. Fig. 6 is an elevation of a weirplate and adjusting mechanism therefor, taken similarly to, butdiffering from the apparatus shown in Fig. 2. Fig. 7 is a plan view ofthe apparatus shown in Fig. 6. Fig. '8 is a view taken similarly to'Fig.2, but illustrating a third form of apparatus. Fig. 9 is a section onthe line 9-9 of Fig. 8. Fig. 10 is a View taken similarly to Fig. 9 butshowing a construction differing slightly from that of Figs. 8 and 9.Fig. 11 is a view taken similarly in general to Fig. 2, illustrating onearrangement for adjusting the measuring apparatus to compensate forchanges in density of the liquid flowing. Fig. 12 is a view takensimilarly to Fig. 11. showing a second method of adjusting the measuringapparatus.

Referring to the apparatus shown in Figs. 1 to 5, A represents the bodyportion or tank of an open. feed water heater, which, in constructionand arrangement, may be identical with the common form of this type ofheater which has been well known and in common use for many years. Inthe form illustrated, A represents the water spreading trays, A thewater distribution box, and A the perforated plate supporting coke orother suitable purifying and filtering material A. A represents theoverflow discharge orifice from the tank, and A the main dischargeorifice through which the water heated in the heater is discharged. Brepresents the cold water supply pipe. C represents the pipe supplyingsteam for heatingthe water. 0 is an oil separator of common form. Drepresents the overflow box into which the port A opens, and from whichthe oil and other impurities drain from the separator C. D 1s a wastepipe leading from the box D and controlled. by a valve D operated, as isusual, by a float (notshown) in the box D.

In the form shown in the drawings, the measuring box or weir receptacleE is secured to the side of and forms a part of a unitary structure withthe heater tank A. The receptacle E is divided into two compartments Eand E by the weir E, which does not extend to the top of the receptacleand has one or more V-notches or orifices E formed in its upper edge, asshown-best in Fig. 2. Y represents a steam pipe connection forequalizingthe pressure in the steam space of the tank A and receptacle E. Frepresents the service discharge connection from the compartment E. Thedischarge port A of tank A opens directly into the lower end of thecompartment E. The supply of water to the tank A is controlled inresponse to the accumulation of water in the compartment E by means of avalve G in the water supply pipe B, the valve being opened and closed bya 'float G in the float box G. The latter is in communication with thecompartment E and the valve G is opened and closed as the water level incompartment E falls below or rises to a predetermined height.

In so far as above described, the construction shown in Fig. 1 isessentially the same as that disclosed in my patent and copendingapplication referred to above. With this apparatus the height of thewater level in the compartment E above the level of the apex of the weirnotch IE will vary in accordance with a known law with the variations inthe rate of flow of water from the compartment E into the compartment E.

on and overlap the margin of the notch E formed in the weir E proper.The plate L is secured directly to the weir E proper as by rivets L. Thestrip L is formed with an undercut socket L concentric with the apex L'of the weir notch, and in this socket is received the chamfered circularextension L of the weir edge strip L. The latter fits snugly against theweir E the adjacent surfaces being carefully machined to restrictleakage, and in addition to being held in place by the pressure of thewater on it, one or more rivets M (one being shown) may be secured tothe strip L. The rivet M, as shown, passes through a slot M in the weirE and has an enlarged head which bears against the discharge side of theweir E. To automatically turn the weir edge strip about the apex, anysuitable thermostatic mechanism may be employed. In the conventionalform illustrated the thermostatic mechanism N comprises a U shapedmember N anchored at its bottom as by rivets N to the weir E. To theends of the legs of the member N are secured the ends of the legs of aU-shaped member N and to the bottom of the latter is secured one end ofa rod N. The upper end of the rod N is secured to the weir edge strip Las by the rivet N.

The U-shaped member N is formed of some material such as iron having arelatively small coefficient of expansion, and the members N and N areformed of material such as zinc, having a relatively large coeflicientof expansion. In consequence the edge strip L is turned about the apex Ltoward and away from the strip L as the temperature of the water risesand falls, and by properly proportioning the parts the angle of the weirmay thus bevaried to the extent necessary to obtain a closeapproximation of the theoretical change in flow required to insure arate of flow with a given hydrostatic pressure at the mouth of the tubeH which does not vary with the term perature of the water.

As is clearly shown by Figs. 4 and 5, showing exaggerated adjustments ofthe movable weir edge plate, with the weir adjusting apparatus disclosedin Figs. 1 to ,5, the angle of the portion of the notch formed wholly inthe strip L is not varied by moving the strip, but, as this portion ofthe notch is small, and since in general, only a small fraction of thetotal flow takes place through it, the fact that this portion of theweir notch is not varied as the rest of the weir notch does notappreciably aflect the accuracy of the results obtained wit-h theapparatus.

In the construction shown in Figs. 6 and 7, 0 represents a plate adaptedto be secured to the weir and having the weir notch proper formed in it.To permit the angle of the notch to be adjusted, I form in the plate 0at one side of the weir notch a narrow slot which may in fact, be a sawkerf. This slot comprises a portion 0 which approaches quite closely tothe margin of the weir notch adjacent its apex, a portion 0', moreremote from said margin and a connecting portion 0 To prevent leakagefrom occurring through the slot 0, O and O I braze the edges of a trouh-shaped body P of flexible sheet metal, sue as copper, to the dischargeside of the plate 0 at the margin of the slot. The thermostatic member Nis anchored at one end to the body of the plate 0 and at the other endto a portion of the plate 0 lying between the slot 0, O O and the weirnotch. In consequence, the elongation and contract-ion of the member Noccurring as the temperature of the Water flowing rises and falls, tendsto narrow and widen the notch by bending the flexible portion of theplate between the notch and slot portion 0 0 represents a slotted guidefor the movable portion of the weir notch plate.

In the form of apparatus shown in Figs. 8 and 9 the weir propercomprises a vertical body portion E and an inclined portion E. The weirnotch member is in the form of a plate Q which extends generallyparallel to the weir portion E and is provided with trunnions Q, thecommon axis of which is in the plane of the supply side of the plate Qand passes horizontally through the apex point Q of the margin of theweir notch. The trunnions Q are journaled in bracket ears E carried bythe weir proper. N represents a thermostatic member in the form of abellows, containing an expansible liquid, which is connected between thelower edge of the plate Q and the portion E of the weir. To preventleakage, a bellowsfolded expansible body R of flexible sheet metal issecured at the edge of the plate Q and its opposite edge to the weirportion E .at the margin of the weir notch. With this construction itwill be apparent, that, as the bellows N shortens and elongates, theplate Q will be oscillated about its pivotal axis to therebycorrespondingly decrease and in crease the effective angle of the weirnotch as is desirable when the height of water level is directlymeasured as by the float S The apparatus shown in Fig. 10 differs fromthat shown in Figs. 8 and 9, in that the normal position of the upperportion of the weir and of the plate Q is vertical. The plate Q maybeidentical with the plate Q, above described, except that the trunnions Qcarried at its opposite edges, are back of the rear side of the plate.In consequence on the small adjustment of the weir plate Q produced bythe thermostatic device N the effective angle of the weir notch is notappreciably altered, but the elevation of the apex Q of the weir notchis appreciably raised and lowered as the temperature of the water fallsand rises. Withthis apparatus,

as explained above, it is possible to compensate for the errorsexperienced from the changes in density of the water accompanying thechange in its temperature, and where the rate of flow is fairly constantand does notvary greatly from the average rate of flow and averagetemperature, will give highly accurate results. As the thermostat isarranged in Fig. 10, the weir is lowered on an increase of temperature,as is desirable when the accumulation of water on the supply side of theweir is determined by measuring the height of water level on the supplyside of the weir. The thermostat should, of course, be arranged as shownin Figs. 8 and 9, when the hydrostatic method .of determining theaccumulation of water on the supply side of the weir is employed.

In the arrangeme nts shown in Fig. 11, the weir E is intended to bestationary, and the float S is employed to determine the variation inwater level on the supply side of the weir. In this form of apparatus Iconnect the rod S by which the indicating, recording or registeringapparatus is operated with the stem S of the float by connections 'S andS, arranged to operate thermostatically to cause S and S to separate asthe temperature of the water decreases, and to approach as thetemperature of the water increases. By employing a suitable ther--mostatic coupling, and it will be undering mechanism through the arm S,and is formed of strips S and S of dissimilar metals, so that the stripS will expand and contract on changes in temperature to a greater extentthan the strip 8.

Those skilled in the art will understand that to obtain results ofextreme accuracy it is essential in calibrating the apparatus, and indetermining the amount of movement to be given to the thermally adjustedparts of the apparatus, to take account of the expansion and contractionof the weir itself, and in some cases of the weir chamber and of themeasuring apparatus, where the accumulation of water is measured by afloat, for theoretically perfect results, some account must be taken ofthe variations in the extent to which the float itself varies insubmergence on changes in density of the liq uid. In general it isdesirable in calibrating the apparatus to so adjust it that the highestpracticable accuracy is obtained at the average rate of flow and averagetemperature of the liquid flowing.

The means disclosed but not specifically claimed herein for adjustingthe weir to decrease the flow occurring with a iven height of liquidlevel on the supply si e of the weir as the temperature of the liquidflowing increases, in conjunction with means for measuring1 thehydrostatic pressure at a predetermine level below the normal liquidsurface level on the supply side of the weir, are specifically claimedin my said copending application, Serial No. 605,878, filed February1st, 1911.

While in accordance with the provisions of the statute, I haveillustrated and described above the best forms of my invention, nowknown to me, it will be apparent to those skilled in the art thatchanges may be made in the form of apparatus disclosed herein, whileutilizing the gist of my invention, and that under certain circumstancescertain features of my invention disclosed herein may advanta eously beemployed without a correspondlng use of other features.

Having now described my invention what I desire to secure by LettersPatent, is:

1. Apparatus for measuring the flow of liquids, comprising incombination, a weir over which the liquid flows and means for measuringthe accumulation of liquid on the supply side of the weir, saidapparatus in-' t the relation between the weight of liquid flowing witha given accumulation of liquid on the supply side of the weir and themeasurement made thereof as the changes in the density of the liquidresulting from its changes 1n temperature tend to make, substantially asdescribed.

2. Apparatus for measuring the flow of liquids comprising incombination, a weir over which the liquid flows, means for measuring theaccumulation of liquid on the supply side of the weir, and thermostaticmeans for ad'usting the weir to compensate for the variation in theweight of liquid flowing with a given accumulation which the change inthe density of the liquid consequent on its changes in its temperaturetends to make.

3. Apparatus formeasuring the flow of liquids,comprising in combinationanotched weir over which the liquid flows, said weir being adjustable tovary the weir notch angle, means for measuring the accumulation ofliquid on the supply side of the weir, and means for adjusting the weirand thereby vary the weir notch angle on variations in the temperatureof the liquid flowing to com 'ensate for changes in density of theliquid, resulting from said variations in its temperature.

4. Apparatus for measuring the flow of a liquid of varying temperature,comprising in combination a weir formed with a V- notch orifice havingrelatively adjustable sides, means for measuring the accumulation ofliquid on the supply side of the weir and thermostatic mechanism forseparating and drawing together the side ed es of the weir notch as" thetemperature of t e liquid flowmg varles.

5. A notched weir adapted for use in liquid flow measuring apparatushaving relatively adjustable notch margin portions and thermostaticmechanism for adjusting said portions.

6. Apparatus for measuring the flow of liquid, comprising a weirprovided with a discharge notch and means for adjusting the weir to varythe cross-sectional shape of a discharge stream of any cross-sect1onalarea passing through said notch.

GEO. H. GIBSON.

Witnesses:

FRANK S. BRoAoHURs'r, WILBERT SAILER.

copies of this patent may he obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0.

